CF1928C.Physical Education Lesson
普及/提高-
通过率:0%
AC君温馨提醒
该题目为【codeforces】题库的题目,您提交的代码将被提交至codeforces进行远程评测,并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供,我们无法保证该服务的稳定性,若提交后无反应,请等待一段时间后再进行重试。
题目描述
In a well-known school, a physical education lesson took place. As usual, everyone was lined up and asked to settle in "the first– k -th" position.
As is known, settling in "the first– k -th" position occurs as follows: the first k people have numbers 1,2,3,…,k , the next k−2 people have numbers k−1,k−2,…,2 , the next k people have numbers 1,2,3,…,k , and so on. Thus, the settling repeats every 2k−2 positions. Examples of settling are given in the "Note" section.
The boy Vasya constantly forgets everything. For example, he forgot the number k described above. But he remembers the position he occupied in the line, as well as the number he received during the settling. Help Vasya understand how many natural numbers k fit under the given constraints.
Note that the settling exists if and only if k>1 . In particular, this means that the settling does not exist for k=1 .
输入格式
Each test consists of multiple test cases. The first line contains a single integer t ( 1≤t≤100 ) — the number of test cases. This is followed by the description of the test cases.
The only line of each test case contains two integers n and x ( 1≤x<n≤109 ) — Vasya's position in the line and the number Vasya received during the settling.
输出格式
For each test case, output a single integer — the number of different k that fit under the given constraints.
It can be proven that under the given constraints, the answer is finite.
输入输出样例
输入#1
5 10 2 3 1 76 4 100 99 1000000000 500000000
输出#1
4 1 9 0 1
说明/提示
In the first test case, k equals 2,3,5,6 are suitable.
An example of settling for these k :
k / № 1 2 3 4 5 6 7 8 9 10 2 1 2 1 2 1 2 1 2 1 2 3 1 2 3 2 1 2 3 2 1 2 5 1 2 3 4 5 4 3 2 1 2 6 1 2 3 4 5 6 5 4 3 2 In the second test case, k=2 is suitable.